How many different video drivers there are?
 

How many different video drivers there are for Linux.
I have nvidia card, and I see there are several video drivers.
Why there are so much different drivers? And which are their advantages and disadvantages?

Nvidia has a proprietary driver , there are open source drivers available as well like nv and nouveau. Itś upto the user to choose the one he wants to use.

Essentially for Nvidia there are 3 drivers. NV is basic & old, providing only 2D acceleration. Nouveau is a newer one designed to address many of the limitation of NV such as 3D support, it just sorta works now, not many cards are supported yet. Both of these driver are open source & free software.

Nvidia themselves provide an official NVIDIA driver. This works very well on almost all their cards & generally provides a more complete feature set than the other 2. Unfortunately, it's not open source/free software, this is why the other 2 exist.

If you are not concerned with using only open source software, then you'll get the best results using the NVIDIA driver.